Alterations of glutathione S-transferase and matrix metalloproteinase-9 expressions are early events in esophageal carcinogenesis

Figure 1 Expression of GST in different esophageal tissues. A: GST strong positive staining was observed in the normal esophagus (200 ×); B: Normal esophageal epithelium (top) with Barrett’s metaplasia (bottom) (200 ×); C: Normal esophageal epithelium shows strong positive immunostaining compared to the weaker GST expression in Barrett’s metaplasia (400 ×); D: Adenocarcinoma showing almost no expression of GST (200 ×); GST was mainly expressed within the cytoplasm.